Device of inflaming large-bore propelling charge



Aug. 13, 1968 v, AKHAGEN 3,396,659

DEVICE OF INFLAMING LARGE-BORE PROPELLING CHARGE Filed April 24, 1967 B 2 3 H m ,1 A /VVVHM t W n N 4 1 V 47 67/ w 1 M F United States Patent 3,396,659 DEVICE 0F INFLAMING LARGE-BORE PROPELLING CHARGE Rune V. Akhagen, Eskilstuna, Sweden, assignor to Forsvarets Fabriksverk, Eskilstuna, Sweden, a corporation of Sweden Filed Apr. 24, 1967, Ser. No. 633,291 Claims priority, application Sweden, Apr. 22, 1966, 5,461/ 66 2 Claims. (Cl. 102-70) ABSTRACT OF THE DISCLOSURE Large bore ammunition having an inflaming charge enclosed in container, which is fixed to the bottom or mantle wall of a charge case and covers only a small part of the bottom of the case but which is enclosed by a box covering the whole area of the bottom of the case. The container walls adjoining the room of the box are weak so as to be broken through and allow combustion gases and burning particles of the inflaming charge to enter the box before escaping to the propelling charge room.

The present invention relates to large-bore ammunition having a gunpowder propelling charge and an inflaming charge, which are enclosed in a charge case having a wall or bottom in which a percussion cap is arranged.

For internal ballistic reasons it is a disadvantage if the propelling charge is ignited irregularly, as the efliciency of the ammunition will thereby be impaired. In the case of recoilless weapons, where a part of the wall or bottom of the case is likely to be broken through as is always the case, it is necessary that the pressure for this purpose be generated in a fixed time. There are several factors influencing the effect of the inflaming charges, among others, the size, placing and shape of the charge and these factors are to some extent dependent upon each other. Merely enlarging the size of the inflaming charge will often lead to an impaired result. Its location, among other things, depends on the size and orientation which the propelling charge has in the charge case. It is often desirable to place the inflaming charge immediately behind the propelling charge. When determining the shape of the inflaming charge, regard must be paid to the fact that its spreading over the whole cross-sectional area of the interior of the cartridge case will facilitate the effect of inflaming the propellant but will counteract a uniform ignition of the inflaming charge itself.

In Swedish Patent No. 140,549 is shown a device which has generally proved to function satisfactorily. In the construction shown in this patent, the inflaming charge is arranged in a plastic container, occupying only a minor part of the cross-sectional area of the interior of the charge case and is placed straight in front of the percussion cap. The container is closed by a lid having a discharge opening for the reaction products of the inflaming charge, said opening being dimensioned so as to withhold the major portion of such products for an interval of time. In this way a pressure is built up in the container which furthers a uniform ignition of the charge in it. In order to obtain a reasonable result in this respect, it has proved desirable to not fill the container completely with an inflaming charge. In consequence thereof it might however occur, that there is no inflaming charge directly in front of the percussion cap if the weapon is located in an inclined position. It is also evident that a device as just described causes the propelling charge to be ignited over a comparatively limited front.

The present invention constitutes an improvement over the device disclosed in the above-mentioned Swedish patent.

3,396,659 Patented Aug. 13, 1968 An object of the invention is to eliminate the disadvantages found in the devices of the prior art and on the whole to satisfactorily meet the requirements of inflaming in an article of this kind.

In the accompanying drawing, wherein an illustrative embodiment of the invention is disclosed,

FIG. 1 is a sectional view of the rear portion of a charge case, the view being taken substantially on the line 1-1 of FIG. 2, looking in the direction of the arrows, and

FIG. 2 shows a top plan View of the section seen in FIG. 1.

The drawing shows an inflaming device for ammunition for recoilless weapons of a kind in which ignition is eifected through the mantle wall of the charge case. The device shown in the drawing is connected with the wall 2 and the bottom 6 of a charge case and consists of a receptacle or box 14 having a bottom 1 with a part 12, and which bottom is principally flat, and a cylindrical wall or skirt 3. In the box 14, which is embraced by the mantle wall 3, a plastic container is arranged, the bottom of which conforms to a minor part of the bottom of the box 14 and the wall 9 of the container has a cylindrical shape and is nearly of the same height as the box 14. The container is provided with a lid 7. Through an opening in the mantle wall of the box as well as in the wall portions 3 and 9 respectively of the container, is arranged a connecting tube 4, straight in front of an opening in the wall of the cartridge case, and with an ignition cap 5 located in the tube. The container is more than half filled with an inflaming charge 8. The bottom area 12 of the box 14 is provided with a plurality of small openings 13. The mantle wall 3 of the box is fixed to the bottom of the charge case by an inturned flange 10 and to the mantle wall of the case by an external peripheral flange 11. The thickness of the wall 9 of the container tapers or decreases downward and the wall 9 is thus weaker than the bottom and side wall of the box.

Due to the weak wall 9 of the container, the ignited inflaming charge will break through the wall before a considerable part of it has been ignited. The reaction products, consisting of burning particles of the charge and combustion gases, gather in the box 14 and are temporarily restrained by its wall and bottom, as only a part of them manage to escape through the openings 13 before the inflaming charge 8 is substantially ignited completely through. As the openings 13 are comparatively well distributed over the bottom of the box, the ignition of the propelling charge is effected over a broad front and under the action of a comparatively limited and gradually built-up pressure but at a high temperature of the inflaming gases.

The invention may be varied within the scope of the inventive concept. Thus, the box 14 need not necessarily be fixed to the bottom of the cartridge case but only to the mantle wall. The container 1, 9 may be manufactured separately and attached to the bottom or mantle wall of the box for example, by gluing. It may have a shape other than cylindrical and may be positioned differently than shown, but only if it is arranged so that the inflaming charge is within reach of the percussion cap.

Having thus described an embodiment of the invention, it is obvious that the same is not to be restricted thereto but is broad enough to cover all structures coming within the scope of the annexed claims.

What I claim is:

1. A charge for the inflaming of a large-bore propelling charge enclosed in a charge case having a propelling charge room and provided with a percussion cap, said device comprising a container, the container having an inflaming charge and being connected to the charge case, said container occupying only a minor portion of the cross-sectional interior of the charge case and communicating with the percussion cap, the container being more than half filled with the infiaming charge, said container having a receptacle disposed around it and which receptacle occupies substantially the whole cross-sectional shape of the interior of the charge case, the receptacle having a circumferential wall disposed adjacent to an interior wall surface of the charge case, the container having a side wall encircled by and spaced from the circumferential wall of the receptacle, the receptacle having a plurality of small gas-escape openings, the side wall of the container being materially Weaker than the circumferential wall of the receptacle so that the combustion products of the inflaming charge will first expand in the receptacle before escaping from it.

2. A charge for the inflaming of a large-bore propelling charge in a charge case having a propelling charge room and provided with a percussion cap, the device compris ing a cylindrical container holding an inflaming charge and being connected to the charge case, the container being disposed within a cup-shaped receptacle and being of smaller diameter than the interior diameter of the References Cited UNITED STATES PATENTS 2,289,318 7/ 1942 Pratt 10239 3,295,448 1/ 1967 Giihle 1O239 FOREIGN PATENTS 140,549 5/ 1953 Sweden.

BENJAMIN A. BORCI-IELT, Primary Examiner.

G. H. GLANZMAN, Assistant Examiner. 

